Scrubbing

• 1). Wait for several days of dry, sunny weather, then climb up to the roof with a scrub brush attached to a pole and scrape off the moss. Always scrape in a downward motion so as not to damage the shingles, tiles or other roofing.
  
  
• 2). Once the moss has been scraped loose, either sweep it off the roof with a broom, or wash it away using your garden hose.
  
  
• 3). Since most of the moss is likely to get into the gutters and you are on the roof anyway, clean out your gutters before climbing down.
  
  

Pressure Washer and Chemical Treatment

• 1). If you plan to use a pressure washer to remove moss, first use a mop to apply a moss killer such as Moss Aside.
  
  
• 2). Let the moss killer sit on the roof for a few days, until the moss is dead.
  
  
• 3). Aiming the nozzle of the pressure washer downwards, working from the peak of the roof down, spray away the dead moss.
  
  

Pressure Washer and Bleach Treatment

• 1). Make your own moss killer by mixing equal parts of chlorine bleach and plain tap water in a large bucket.
  
  
• 2). Apply the bleach mixture using a mop, as described above for commercial moss killers.
  
  
• 3). Let the bleach solution sit for several day. When the moss is dead, clear it away with a pressure washer.